2-Mavzu. Kompyuterlarni tashkil qilishning raqamli mantiqiy asoslari

Figure 3. Word to the 32nd category length has , bytes right in order placed 4 GB basic memory .
2-rasmda keltirilgan xotirada Pentium protsessorli kompyuterlardagi kabi, baytlar o‘ngdan chapga qarab joylashtirilgan.
Bu baytlarni teskari tartibda joylashtirish deb ataladi (rus tilida – обратный порядок следования байтов).
3-rasmda esa baytlar to‘g‘ri tartibda joylashtirilgan xotira chizmasi keltirilgan.
Bu xildagi xotira baytlar to‘g‘ri tartibda joylashtirilgan xotira deb ataladi (rus tilida – прямой порядок следования байтов) va u SPARС oilasiga mansub protsessorlarga ega bo‘lgan serverlarda ishlatiladi.
3-rasm. 32-razryadga so‘z uzunligiga ega, baytlari to‘g‘ri tartibda joylashtirilgan 4 Gbaytli asosiy xotira.
Commands from memory reading in the example , memory appeal to do how instead increase see we go out Figure 4 _ basic to memory appeal to do process shown .
Of the processor IP (Instruction Pointer) or Known as PC (Program Counter) dimensions , order on completion need which was command address show for used . This register commands counter or commands is called an indicator .
PC registry written address , ie next completion need which was of the command address , processor address tire using basic memory with connecting port - address registers through memory , memory address to the registry transmitted .
That's it then of memory information to the registry this address on written information is removed . This is information , data tire through processor registers to one , e.g. to the accumulator , i.e. to register A. come falls .
Buyruqlarni xotiradan o‘qish misolida, xotiraga murojaat qilish qanday amalga oshirilishini ko‘rib chiqamiz. 4-rasmda asosiy xotiraga murojaat qilish jarayoni ko‘rsatilgan.
Protsessorning IP (Instruction Pointer) yoki PC (Program Counter) deb nomlanuvchi registri, tartib bo‘yicha bajarilishi kerak bo‘lgan buyruq adresini ko‘rsatish uchun ishlatiladi. Ushbu registr buyruqlar sanagichi yoki buyruqlar ko‘rsatgichi deb nomlanadi.
PC registrida yozilgan adres, ya’ni navbatdagi bajarilishi kerak bo‘lgan buyruqning adresi, protsessorning adres shinasi yordamida asosiy xotira bilan bog‘lanuvchi porti - adres registri orqali xotiraning, xotira adresi registriga uzatiladi.
Shundan so‘ng xotiraning ma’lumotlar registriga ushbu adres bo‘yicha yozilgan ma’lumot chiqariladi. Bu ma’lumot, ma’lumotlar shinasi orqali protsessorning registrlaridan biriga, masalan akkumulyatorga, ya’ni A registriga kelib tushadi.